This invention relates to high output fluorescent lamp fixtures, and more particularly to a softener for a high output fluorescent lamp fixture.
Referring to FIG. 1, a conventional high output fluorescent lamp fixture 10 tends to produce maximum illumination immediately below and along the length of the high output fluorescent lamp 15. This can cause glare while leaving shadows in other areas where illumination is desired. Methods for reducing glare and providing more uniform illumination from a high output fluorescent lamp fixture are well known. For example, referring to FIG. 2, the conventional high output fluorescent lamp fixture 10 includes a housing 20, a reflector 25, one or more high output fluorescent lamps 15, and a sheet diffuser 30.
To provide more even illumination, the sheet diffuser 30 disperses direct lighting emanating from the lamp 15 and indirect lighting reflected by the fixture""s reflector 25. The sheet diffuser 30 can have a perforated or ridged surface for increased light dispersion. Referring to FIGS. 3 and 4, the sheet diffuser may be installed as a lens cover diffuser 35 (FIG. 3) that is positioned at the bottom of the housing 20 or as an overlay diffuser 40 that is installed inside the lamp fixture 10 (FIG. 4).
A desire for increased brightness levels has resulted in the development of high output lamps. However, the increased brightness level from these high output lamps increases the potential for discomfort, harsh glare, or shadows. Conventionally, the glare from the high output lamps is minimized by reducing the transmissive properties of the sheet diffuser 30 such that the lamp""s brightness level is comparable to that produced by a standard high output fluorescent lamp fixture.
In one general aspect, a high output lamp softener includes a base and at least one diffuser extending from the base toward an interior of the base and defining a surface configured to encircle a portion of a circumference of a high output lamp.
Implementations of the high output lamp softener may include one or more of the following features. For example, the surface of the diffuser may be configured to be positioned below a portion of the circumference of a high output lamp. The surface of the diffuser may be configured to follow the contour of a high output lamp. The surface of the diffuser may be configured to be a constant distance from a high output lamp when the high output softener is mounted in a lamp fixture comprising a high output lamp. The diffuser may include a pair of diffusers.
The diffuser may include a translucent material. The translucent material may transmit between approximately 60% and 80% of direct light emitted from a high output lamp. The translucent material of the diffuser may reduce the total light level from a high output fluorescent lamp fixture by between approximately 25% to 35% more than that provided by a standard fluorescent lamp fixture. The translucent material may include a polymer and an additive that reduces the transmissivity of light through the diffuser.
The base may include a transparent material. The diffuser may include a curled edge that extends from the surface toward the fluorescent lamp. The base may include a lens cover for a lamp fixture. The high output lamp softener may further include one or both of a high output lamp and a reflector. The base may be configured to be mounted to the lamp fixture and the diffuser may be configured to be mounted to the reflector. The lamp softener may include one or more fasteners for mounting the lamp softener to one or both of the lamp fixture and a high output lamp. The base and the diffuser may be co-extruded integral components.
In another general aspect, a high output lamp softener may include at least one diffuser having a surface that is configured to encircle a portion of a circumference of a high output lamp and to be positioned in close proximity to a high output lamp. The lamp softener reduces the apparent lighting of the high output lamp while maximizing the reflected lighting emanating from the high output lamp.
Implementations of the high output lamp softener may include one or more of the following features. For example, the diffuser may include one or more fasteners that are configured to mount the softener to a lamp fixture. The fastener may include one or more clips that are configured to mount the lamp softener to a high output lamp. The surface of the diffuser may extend from underneath the high output fluorescent lamp and arc upwardly toward the sides of the high output lamp fixture. The diffuser may include a pair of diffusers.
The diffuser may include a translucent material. The translucent material of the diffuser may transmit between approximately 60% and 80% of direct light emitted from a high output lamp. The translucent material of the diffuser may reduce the total light level from a high output fluorescent lamp fixture to between approximately 25% and 35% more than that provided by a standard fluorescent lamp fixture. The translucent material may include a polymer and an additive that reduces light transmissivity through the diffuser.
The diffuser may be configured to encircle approximately 180xc2x0 of the circumference of a lamp, between approximately 90xc2x0 and 180xc2x0 of the circumference of a lamp, or approximately 360xc2x0 of the circumference of a lamp. The diffuser may include a flat surface.
In another general aspect, a lamp fixture includes a housing and a softener. The housing is configured to retain a fluorescent lamp. The softener includes a surface and is mounted adjacent to a fluorescent lamp to reduce the transmissivity of light through the surface. The surface includes a polymer and a filler that reduces the transmissivity of light through the surface.
Implementations of the lamp fixtures may include one or more of the following features. For example, the softener may include a fastener for mounting the softener. The fastener may include a clip for mounting the softener to a fluorescent lamp. The lamp fixture may further include a reflector and/or a lens. The diffuser may be configured to encircle approximately 180xc2x0 of the circumference of a lamp, between approximately 90xc2x0 and 180xc2x0 of the circumference of a lamp, or approximately 360xc2x0 of the circumference of a lamp. The diffuser may include a flat surface.
In another general aspect, the output of a lamp can be softened by providing a lamp softener that includes a surface that reduces the transmissivity of light through the surface and placing the lamp softener adjacent to the lamp such that the lamp softener encircles at least a portion of the circumference of the lamp. The surface includes a polymer and a filler that reduces the transmissivity of light.
Softening of the output of the lamp may include one or more of the following features. For example, placing the lamp softener adjacent to the lamp may include mounting the lamp softener to the lamp. The lamp softener and the lamp may be mounted in a lamp fixture. Mounting the lamp softener in the lamp fixture may include mounting the lamp softener to the lamp fixture and/or mounting the lamp softener to the lamp. The softener may include a translucent material and the translucent material may transmit between approximately 60% and 80% of direct light emitted from a high output lamp. The softener may encircle approximately 180xc2x0 of the circumference of the lamp, between approximately 90xc2x0 and 180xc2x0 of the circumference of the lamp, or approximately 360xc2x0 of the circumference of the lamp.
The lamp softener provides considerable advantages. For example, the shape of the high output lamp softener works in conjunction with the luminaire""s contours to distribute the concentrated brightness of the true source and to create a much softer looking apparent source. The shape also maximizes the reflectance of the luminaire""s upper surfaces to eliminate shadows and to provide a more uniform brightness across the face of the luminaire. The high output lamp softener also reduces the harsh glare of high output lamps to more comfortable brightness levels without a significant reduction in the lighting intensity. The high output lamp softener also reduces shadows and provides more even light distribution than that provided by a high output fluorescent lamp fixture with a conventional sheet diffuser. The lamp softeners are advantageously configured and positioned adjacent to the lamp such that they reduce the apparent illumination seen below the lamp while simultaneously allowing the light from the lamp to reflect from the reflective surface of the lamp fixture, including those of the reflector or baffles and the housing. Thus, the softener provides illumination that is a mixture of direct lighting through the softener and light reflected from the reflective surfaces of the fixture.
The lamp softener also advantageously can be used to reduce the inventory of lamp bulbs that must be carried or stored in a large building or facility. For example, high output lamps, such as T-5 high output lamps, can be used throughout a building in both direct and indirect lighting applications. Because the illumination provided by the lamp will be too bright in some applications, a lamp softener can be placed around or adjacent to the lamp to provide a more comfortable level of illumination. Furthermore, because the softener advantageously does not reduce the reflected lighting, the lamp fixture will provide even and comfortable lighting. Because the softener can be optionally used, the maintenance staff of the building or facility can use the same lamp in many applications and then can use the softener in only those applications for which a softened apparent lighting is desired.
The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features and advantages will be apparent from the description, the drawings, and the claims.